Bating composition



' leathers.

ester of Patented Feh. 13, i945 UNITED I STATES PATENT oFFics 7 H2,369,256 EATING COMPOSITION Friedrich Schmitt, Chemnitz, Germany,assignor to American Hyalsol Corporation, Wilmington, Del., acorporation of Delaware No Drawing. Application July 13, v1940,

Serial No. 345,416

Claims. (01. 195 63) by weakening the structure of the resultingleathers and at the same time adversely affecting its texture and grain.Moreover, these deleterious eflects'are more noticeable on some hidesthan on others, particularly on the rather finegrained hides used inproducing garment, novelty, and top leathers for shoe manufacture. In

such hides the innerlayers are usually loosened in the bating bath to anextent which prevents the final leather product from having therequisite strength. I a Numerous bating compositions have been proposedwherein the primary enzymatic action is provided by various animalpancreatins, especially those derived from domesticated animals such ashogs, cattle and the like, preferably in mixture with ammonia salts.Such bat ng compositions have frequently proved unsatisfactory becauseof their destroying or weakening effect on the leather forming fibers,when the bating.

is too much prolonged or when. too large amounts of these bating agentsare used. I

In accordancewith' the present invention improved and better balancedbating compositions are provided, especially for the treatment ofsensitivev hides. The enzymatic properties of these compositions can beregulated to remove effectively the undesirable fibers of skins withoutadversely affecting the quality of" the resulting- These compositionspreferably contain pancreatins, asoluble salt. of a sulphuric acid ahigher molecular fatty alcohol and a buffer salt. Sometimes it isadvantageous to include an inert ingredient such as wood flour tofacilitate thorough mixing of the several components.

The preferred fattyslcoholsulphuric acid esters are" those deriyedfromsaturatemalcohols 0 f 12 to 14 carbon atomso'r those derived .from

unsaturated fatty alcoholsv of a higher molecular weight. The amount ofsoluble salt of fatty alcohol sulphuric acid ester usedvsries with theIt has been found that the old fash-,

enzymatic agents heretofore proposed cause the collagen fibers to behydrolyzed, thereq- Q the collagen.

type of pancreas used and the hides bein treat-' ed. One part of solublesalt of fatty alcohol sulphuric acid ester to three partsof the pancreatin, usually proves quite adequate. The amount of .5 the bufiersalt will depend upon the salt used,

the type and condition of the hide and-the nature of the treatment bath.A composition which,

has proven quite successful, for. the bating of hides has contained theseveral ingredients in l the approximate ratio, by weight,of 3.6 partsof suitable pancreas, 1 part of soluble salt of a fatty alcoholsulphuric acid ester of 12 to 14 carbon atoms, and 32 parts of ammoniumsulfate. "The homogeneity of this composition "was improved when itcontained approximately 44 parts of wood flour.

e The compositions of the present invention have an excellent balancebeing very effective in the removal of undesirable fibers withoutdeleteriously afi'ecting the collagen. This balance seems to be impartedby improving the enzymatic action of the bating compositions on elastinsand other undesirable constituents of the skin without a concomitantincrease in their activity, on This theory seems to beborne out by thefact that bating compositions incorporating Dancreatins having mildenzymatic properties, such as whale pancreas, have proven to be veryeffective in the bating of certain sensitive hides.

For instance, in accordance with a special em-' bodiment of theinvention whale pancreas is used to provide the essential enzymaticaction in bating compositions. This enzymatic agent is.

as provided in a bating composition containing a a neutral salt, asoluble salt of a fatty alcohol sulphuric acid ester, and an appropriateextender or dispersing medium; The enzymatic effect of whale pancreas isexerted mainly upon the upper 40 layer, 1. e. the grain, of the hides orskins. The pigment and hair roots being present in-the grain layer areremoved therefrom; very completely but without impairing the 'trengthand fullness of the final leather product. Where the enzymatic "actionof the'w'hale pancreas does'not penetrate sumciently into the innerparts of the hides or skins, it sometimes proves desirable to add minorProportions of other 'pancreatins; such as beef pancreas, to promote theenzymatic eilect on the i l iri ner sheets of the hides or skins. Thisis especially desirable in the bating of skins destined for manufactureof gloves. A very satisfactory bating pancreatin has been providedfox-bating sensitive skinsusedfor top leathers by combinliingspcrtsofwhalepancreaswithzpsrtsofbeef pancreas. Agh'ating compositionwhich has found wide acceptability in the leather treating arts consistsof the following ingredients:

' Parts by weight at, Whale and beef pancreas in the ratio of Thecomposition is prepared by intimately mixing the wood flour and thepancreatins in a suitable mixing chamber, such as. a, four-corneredaluminium drum, and then adding finely pulveraacaase closed herein areillustrative of the invention and that equivalents may he used. Theapplicant desires that his invention be accorded a scope commensuratewith his contribution to the, art, as limited only by the appendedclaims. Iclaimz' 1. A hating composition for treating the skins ofsheep-and calves and like sensitive skins for the production of topgrain leather, which composition is capable of effectively hating thetop grain without appreciably loosening the inner fibers, comprising anenzymatic agent composed primarily of whale pancreatin, and a solublesalt of a sulfuric acid ester of a higher molecular of sheep and calvesized ammonium sulfate and thepowdered salt of fatty alcohol sulphuricacid ester to this mixture. The mixture is agitated over a period ofabout 30 minutes whereby a homogeneous distribution is attained. Such acomposition has been shownv to possess 1,000to 1,050 enzymatic testunits when evaluated in accordance with the Kubelka-Wagner method.

The enzymatic hating compositions of the instant invention areparticularly suitable for the treatment of sensitive skins such asthose'derived from sheep and calves. The hidesbated with theenzymatic agentsof the present invention produce leathers showing a fine strong grainand adequate fullness. The hating compositions are especially suitablefor treating meagre calf skin for the manufacture of box calf, and formaking Chevrettes from lamb skins. However, the hating compositions arealso suitable for cattle and horse hides, and skins from goats, reptilesand fishes. It is necessaryto regulate the ratio of pancreatin tohuflfer salt according to the characteristics of the original hides orskins. For example, whengbating a cow hide to produce sole leather, agreat quantity of a buffer salt, such as ammonium sulfate and only verylittle pancreatin is necessary, whilst when hating a goat skin much morepancreatin than ammonium sulfate is to be used. For example, a mixtureposfatty alcohol or at least 12 carbon atoms.

2. A hating composition for treating the skins the production'of topgrain leather, which composition is capableof effectively hating the topgrain without appreciably loosening the inner fibers, comprising anenzymatic agent composed primarily of a whale pancreatin, a solublesalt. of a sulfuric acid ester of a'higher molecular fatty alcohol of 12totl4 carbon atoms, and a buffer salt.

3. A hating composition for treating the skins of sheep and calves andlike sensitive skins for the production of top grain leather, whichcomposition is capable of effectively hating the top grain withoutappreciably loosening the inner fibers, comprising a composition conaining, by weight, approximately 3.6 parts ofpancreatin composedprimarily of a whalepancrea's, 1 part of a water soluble salt of a fattyalcohol of atleast 12 carbon'atoms, and 32 parts of ammonium sulfate.

sessing an enzymatic test hf 2,000 to 2,500 units,

when evaluated by the Kubelka-Wagner method, is necessary for hatinggoat skins. The hating process using the enzymatic agent of the presentinvention is best carried out in a fresh bath of mild alkalinity havinga pH value between 8 and 9 and at a temperature of about 20 to 38 C. Theamount of the enzymatic agent-added to the hating bathwill depend uponthe effect desired, the kind of hides being treated and the length oftreatment. The appropriate Y concentration 'can easily be determined;

under Practical Operating conditions.

It is to be understood that-the examples dis of sheep and calves and 4.A hating composition for treating the skins of sheep and calves and likesensitive skins for the production of top grain leather, which com.-position is capable of 'eifectively hating the top grain withoutappreciably loosening theinner fibers, comprising an, enzymatic agentcomposed primarily of a whale pancreatin and secondarily of a beefpancreatin, a water soluble salt'of a higher molecular sulfuric acidester of an aliphatic alcohol of 12 to 14 carbon atoms, and ammoniumsulfate.

5. A hating composition for treating the skins like sensitive skins forthe production of top grain leather, which composition is capable ofeffectively hating the top grain without appreciably loosening the innerfibers, containing, by Weight, approximately?! partsofpancreatin-consisting of whale and beef pancreatin in the ratio of about4 to 1, 240 parts of ammonium sulfate, 33 parts of wood flour, and

7.5 parts of a=water soluble salt of a sulfuric acid esterof 12 to, 14carbon atoms.

FRIEDRICH 7 scmm'rr.

and like sensitive skins for

